Belting



Dec. 2, 1969 P. M. ROBINSON 25,731

BEL'IING Original Filed July 14, 1961 2 Sheets-Sheet l 0------ o q u Qno-0--- wooooooaoo lawaoaaooooo ooooaoooo /9 /ooo0o0 oooo Inven'forer:r-N/c/gael IF! bi'nson m Whoa vM Dec. 2, 1969 P. M. ROBINSON Re. 26,731

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United Statcs Patent 26,731 BELTING Peter Michael Robinson, SuttonColdfield, England, assignor to The Dunlop Company Limited, London,England, a British company Original No. 3,297,513, dated Ian. 10, 1967,Ser. No. 124,038, July 14, 1961. Application for reissue Apr. 5, 1968,Ser. No. 724,676 Claims priority, application Great Britain, July 29,1960, 26,413/60 Int. CL B32b /12 US. Cl. 161-57 6 Claims Matter enclosedin heavy brackets appears in the original patent but forms no part ofthis reissue specification; matter printed in italics indicates theadditions made by reissue.

ABSTRACT OF THE DISCLOSURE Conveyor belting suitable for passengercarrying even when supported at the edges only is disclosed, wherein aflexible plastic material has a composite reinforcement embeddedtherein. The reinforcement is formed of at least two parallel layers offlexible metal cords which extend transversely across the belt and atleast one layer of a woven fabric which extends between the metal cordlayers. The metal cords of each layer are equally spaced and parallel toadjacent cords and extend continuously along the length of the belting.

This invention relates to conveyor belting suitable for use inpassenger-carrying conveyor installations.

According to the invention conveyor belting comprises a flexible plasticmaterial having embedded therein a composite reinforcement comprising atextile reinforcement together with at least two layers of metal cords,the metal cords in each layer lying substantially parallel with eachother and substantially at right angles to the length of the belting,and a textile constituent of the composite reinforcement being disposedbetween each metal cord layer and the adjoining metal cord layer.Usually the metal cords are of steel.

Two steel cord layers may be employed, with a single and separate layerof textile reinforcement between them, embedded in flexible plasticmaterial such as vulcaniscd natural or synthetic rubber, or syntheticresin. Alternativcly, a more complex reinforcement may be used,consisting for example of three layers of steel cords and two distinctlayers of textile reinforcement, the steel cord and textile layersalternating with each other. A composite reinforcement which is in thenature of a compound or solid woven fabric in which part or all of theweft material is constituted by the metal cords may also be used,

rather than a composite structure comprising alternating but distincttextile and wire components; specific examples of these compound orsolid woven fabrics are (l) a fabric comprising two steel cord wefts andbetween them a weft of textile material, all three being woven withtextile warps into a unitary structure, and (2) a fabric comprising twosteel cord wefts woven together with a binder of textile material andalso woven each with its own filter of textile material.

A wide variety of textile reinforcements may be used, and textileconstituents in belting according to the present invention may comprise,for instance, one or more plies of a woven or non-woven cotton, rayon,nylon or polyester fabric.

Specific examples of textile reinforcements according to the inventionwhich may be used in the construction of covneyor belting will now bedescribed with reference to thc accompanying drawings in which:

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FIGURE 1 shows diagrammatically a section of belting containing threeplies of woven cotton fabric used between two transverse layers of steelcord.

FIGURE 2 shows diagrammatically a section of belting containing a singleply of woven polyester fabric used between two transverse layers ofsteel cord.

FIGURE 3 shows diagrammatically a section of belting containing fourplies of woven polyester fabric used in conjunction with threetransverse layers of steel cord, two of the polyester plies lyingbetween each steel cord layer and the next.

FIGURE 4 shows similarly as section of a belting containing two plies ofa non-woven nylon fabric represented by two layers of longitudinal nyloncords used between two transverse layers of steel cord.

FIGURE 5 shows a section of a belting containing a textile warp, twotransverse layers of steel cord separated by one layer of textile weft,all being woven with warps of a textile material into a unitarystructure.

FIGURE 6 shows a section of a belting containing two steel cord weftswoven together with a binder of textile material and also woven eachwith its own filler of textile material.

Referring to the drawings:

FIGURE 1 shows three plies l, 2, 3 of 54 ounce per square yard wovencotton fabric between two transverse layers 4 and 5 of steel cord. Theseplies are impregnated with the rubber or synthetic resin composition 6and a rubber covering layer 7 applied to each side.

FIGURE 2 shows a single ply 8 of 54 ounce per square yard wovenpolyester fabric used between two transverse layers 9 and 10 of steelcord and the whole impregnated with rubber composition 11 and a rubbercovering layer 12 applied to each side of the belting.

FIGURE 3 shows four plies 13, 14, 15, 16 or ounce per square yard wovenpolyester fabric used in conjunction with three transverse layers 17,18, 19 of steel cord impregnated with a vulcanizable rubber composition20 and a rubber covering layer 21 applied to each side.

FIGURE 4 shows two transverse layers 22, 23 of steel cord separated bytwo layers 24, 25 of longitudinal nylon cord and a rubber covering layer62 on each side of the belting.

FIGURE 5 shows two transverse layers of steel cord 27. 28 separated by atextile weft 29 and woven with warps 30 of a textile material to form aunitary compound structure which is covered by outer layers 31 of rubbercomposition on each side.

FIGURE 6 shows two steel cord wefts 32, 33 woven together with textilecords 34 and each layer of steel cords woven with a filler 35, 36 oftextile material, the whole impregnated and covered with a rubbercomposition 37.

The formulation adopted for the rubber or synthetic resin composition,and the method of manufacture, may correspond with those normally usedin the rubber and synthetic resin belting art. Examples of the syntheticresin compositions which may be used are plasticized polyvinyl chloridecompositions in which there are to 150 parts of plasticizer, preferablyto parts, per 100 parts of polyvinyl chloride; vinyl chloridecopolymers, e.g., copolymers of vinyl chloride and vinyl acetate, arealso suitable. In the finished product the vulcanized rubber compositionor synthetic resin composition penetrates into the reinforcement layers,i.e., between their individual cords or threads. By using a thick layerof the flexible plastic between the transverse steel cord and the pliesof fabric a substantially increased transverse rigidity is obtainedwithout any appreciable increase in the longitudinal rigidity of thebelting.

Steel cords may be suitably used in belting according to the presentinvention at spacings corresponding to about 10 cords per inch (measuredalong the length of the belting) e.g., 8 to 24 cords per inch. Theindividual cords may suitably be consitituted by a number of strands(0.3-, 6 to 12 strands) of steel wire of a gauge which may for examplebe 30 to 44 Imperial Standard Wire Gauge.

Belting made according to the present invention has a relatively greatrigidity in a transverse direction but has a relatively low rigidity inthe longitudinal direction. This provides a very stable platform forpassengers carried by the belting, so that the number of rollers neededto support the belting may be less than those employed in conventionalpassenger conveyors. The feature just mentioned also makes it possibleto use rollers in the form of a disc or a ball, so that the belt is notsupported across its full width but only at points across the width;thus the belt may even be supported by a line of discs at the edgesonly, so that there are no rollers below that part of the belt whichactually supports the passengers. Nevertheless, the low longitudinalrigidity of belting according to the invention in the longitudinaldirection minimises the power required to drive the belt and permits theuse of small driving and tension pulleys.

Having now described my invention, what I claim is:

[1. Conveyor belting suitable for carrying human passengers which isflexible longitudinally and substantially rigid transversely and capableof providing a stable platform for the conveyance of passengers whensupported at the edges only comprising a flexible plastic materialhaving embedded therein a composite reinforcement comprising at leasttwo transversely extending layers of metal cords arranged substantiallycontinuously and uniformly along the length of the belting, the metalcords in each layer lying substantially parallel with each other andsubstantially at right angles to the length of the belting, and at leastone layer of textile cords extending longitudinally of the beltingbetween any two metal cord layers] 2. Conveyor belting suitable forcarrying human passengers which is flexible longitudinally andsubstantially rigid transversely and capable of providing a stableplatform for the conveyance of passengers when supported at the edgesonly comprising a flexible plastic material having embedded therein acomposite reinforcement comprising at least two transversely extendinglayers of metal cords constituted by 6-12 strands of steel wire of 30-44Imperial Standard Wire Gauge arranged substantially continuously anduniformly along the length of the belting at a frequency of 8-24 cordsper inch, the metal cords in each layer lying substantially parallelwith each other and substantially at right angles to the length of thebelting, and at least one layer of textile cords extendinglongitudinally of the belting between any two metal cord layers.

3. Conveyor belting according to claim [1] 2 wherein the compositereinforcement comprises two steel cord layers with a single and separatelayer of textile between these two layers.

4. Conveyor belting according to claim [I] 2 having two transverselyextending layers of metal cords.

5. Conveyor belting according to claim [1] 2 having at least two layersof textile cords between the layers of metal cords.

6. Conveyor belting for carrying human passengers comprising a flexibleplastic material having outer and inner surface: and having embeddedtherein outer and inner layers of transversely extending, mutuallyparallel steel cord: closely and uniformly spaced but individually .4enveloped by said plastic material, and a layer of textile cordsintermediate said outer and inner layer: of steel cards, the outer andinner layers of steel cords being parallel to the respective outer andinner surfaces of the belt, the cordsof said layers being arranged sothat the greatest distance in the longitudinal direction olthe bellingbetween successive steel cords in the some layer does not exceed .1122inch, measured between the widest points of two adjacent cords, wherebythe belting is rendered substantially rigid transversely thereof whilelongitudinal flexibility is preserved.

7. Conveyor belting for carrying human passengers comprising a flexibleplastic material having embedded therein a composite reinforcement, saidcomposite reinforccment including at least two layers of transverselyextending individually flexible metal cords, and at least one layer ofwoven textile fabric extending throughout the length 0/ the beltingbetween two metal cord layers, each cord of said metal cord layers beingequally spaced from the adjacent cords and the layers being arrangedsubstantially contiriuously and uniformly along the length of thebelting, the metal cords in each layer lying substantially parallel toone another and to the cards in any other layer, and substantially atright angles to the length of the belting, the composite reinforcementbeing bonded together by said plastic material, the cords of said layersbeing arranged so that the greatest distance in the longitudinaldirection of the belting between successive metal cords in the somelayer does not exceed .1122 inch, measured between the widest points oftwo adjacen cords, the belt structure being capable of providing astable platform for the conveyance of passengers even when supported atits side edges only, while remaining flexible in the longitudinaldirection.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS 905,946 12/1908 Stevenson 139-412 XR 2,425,575 8/1947 Sulofl'. 2,511,581 6/1950 Grigsby 161-91 XR 2,514,429 7/1950 Waugh161-57 XR 2,655,195 10/1953 Curtis. 2,784,130 3/ 1957 Kalin. 2,793,1505/1957 Deaves 161-91 XR 2,850,420 9/1958 Hacker 161-144 XR 3,047,4467/1962 Henson 161-78 XR FOREIGN PATENTS 1,178,635 12/1958 France.

5 64,663 11/1932 Germany.

945,980 7/ 1956 Germany.

2,034 1859 Great Britain. 12,255 1914 Great Britain.

703,390 2/1954 Great Britain.

781,170 8/1957 Great Britain.

804,173 11/ 1958 Great Britain.

ROBERT F. BURNETT, Primary Examiner U.S. Cl. X.R.

